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R. c. VAN SICKLE Re. 18,630

cmcux'r iNTERRUP'I'ER Oct. 18,1932.

Original Filed May 19, 1928 INVENTOR Roswell 6. VdflSI'G/ME.

AiToR NE WES aJ Reissued Oct. 18, 1932 UNITED STATES! aNT OFFICE;

ROSWELL G. VAN SICKLE, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTTNG- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

omeurr m-rnanurrna Original No. 1,764,369, dated June 17, 1930, Serial No.

filed May 12, 1932.

a My invention relates to circuit interrupters and more particularly to the contact members thereof.

It is well known in the electrical art that-a current, when passing through parallel conductors, will produce a flux thereabout that causes the parallel conductors to be drawn toward each other.

It is one object of my invention to provide means associatedwith a pair of parallel contact fingers that shall act to draw them tightly against the cooperating contact surface to bers 3 and 4 against a wedge-shaped conductinsure a good electrical contact therewith.

It is a further object of my invention to provide contact fingers and a bridging member with which they cooperate with means that will increase the contact pressure in a direct proportion to the amount of current flowing through the circuit. 1

These and other objects that may be made apparent throughout the further description of my invention are attained by means of the apparatus hereinafter described and illustrated in the accompanying drawing-where- 1n:

Figure 1 is a View, in elevation, of a particular form of contact member embodying my invention and shown in closed position.

Fig. 2 is a view, similar to Fig. 1 but showing the contact member in open position, and- Fig. 3 is a sectional view of the embodiment of my invention shown in Fig. 1, taken along the line IIIIII My invention comprises, general, acontact member 1 that is supported on the end of a terminalstud 2 and comprises terminal members 3 and 4 that are supported on spring members 5 and 6 bolted to the conductor member 2 by the bolt 10. Spring members 7 and 8 are employed to bias the contact meming member 9 in order to/make suitable contact therewith. j

When this type offinger is employed on a circuit interrupter designed for heavy currents, increased pressure on the contact member must be provided in order to reduce the potential drop in the junction to a minimum. It is found that, when the sprin members 5, 6, 7 and 8' are madelarger and eavier in terminals 3 and 4.

278,938, filed May 19,1928. Application Ior reis ue Serial No. 610,963.

order to increase this contact pressure the Many arrangements have been employed to assure good pressure and contact on the surface of such finger-type contacts as are here shown. These structures have, however, all proved costly and ineflective. In accordance with my invention, I employ U-shaped iron members 11 and.12,-d isposed about the terminal-members 3 and 4 and forming a magnetic' path for the flux which surrounds the flexible conducting shunts 13 and 14 when the I current is flowing therethrough. Iron plates.

15 and 16 are fastened to each side of the wedge. member 9, and the sides thereof lie parallel to the tapering side of this member. The. U-shaped iron members ll'and 12 are so mounted that the side portions thereof have their surfaces parallel to the surface of the The air gaps between the U-shapied members 11 and 12 and the iron plates 15 and 16 are of the same width along their entire length because of the parallel arrangement of these iron members. By this arrangement, I- obtain the same pressure between the surfaces of the terminal members 3 and 4 and the wedge member 9 when the wedge 9 is completely or only partially forced between the terminal members 3 and 4. The air gap between the iron members remains the same along the en-' tire path of travel of the wedge member 9 so that the same pressure between the latter and terminal members 3, 4 is producedin all of its positions.

When employing my magnetic circuit, the contact member 1 is assembled in the same way as those heretofore employed in the art. The terminal members 3 and 4 are attached to the shunts 13 and 14 and the spring members 5 and 6 by rivets 17 and 18. The magnetic circuits 11 and 12 are next riveted to the contact members 3 and 4, and-the whole assembly mounted on the contact member 2 by the bolt members similar to those here shown, having each air gap one-eighthof an inch wide, the force on each finger per square inch of iron cross-section is approximately 1.09 I x 10- pounds. It will evident that, when a greater force isreguired for a given current, the cross-section o theiron members 11, 12,-, 15 and 16 may be increased. By such means as will beevident, any pressure may be ob -.v tained on the working face of a cont'act mem her by properly p'roportioning the magnetic circuits to the current flowing in the contact; It will thus be seen that I have provided for an increasing pressure on the terminalof the finger or parallel-path type contact member v by employing an iron circuit surrounding the portions of the contact member that abut current until the saturated.

against cooperating contact member. By locating my. iron members so that their ad- 'acent surfaces are parallel to-the abutting current-carrying surfaces, the same pressure is obtained for various positions of the bridging member relative to the terminal members. This construction results in causing the contact members to produce a greater pressure on the abutting contact surfaces when a greater current is flowing in the line and this pressure increase is proportional to the increase of magnetic circuit becomes My invention is turther novel in that it Q makes possible an increasedpressure at the intimate engagemen current-carrying relation. 15 1 f abutting surfaces of the contacts by increasing the cross-sectional area of thesaid magnetic circuit. v

It is to be understood that such changes in the form, arrangement and connection of the component parts of my invention may be made asshall fallwithin the scopeof the appended claims. f v I I laim as my invention:

1. A parallel-path contact meinbena coop crating member therefor and a loop of iron about the contact member and the cooperating member forming a magnetic path about the point of contact between the said 111W?? bers for drawing them intog mone intimate I i .1 act members formmg 2'. A pair of cont netic circuit ormed about {said members to. draw the-current carrying portions into more 3. The combination with a pair of finger contacts and a wedge-she d contact member:

therewith, o a magnetic circuit formedby iron members associated with the finger'o'ontacts and the wedge-shaped meniber todraw them together when current is passing1 therethrough.

4. T e combination with a pair of finger contacts, of a wedge shaped member passing therebetween, a U-shaped magnetic circuit 76 about each contact member and an iron m'emlager on each side of the wedge-shaped'mem er. a

5. The combination with a pair of contact members forming parallel paths for an electriccurrent,'of a conducting member movable between the fingers to com letea circuit therewith, a U-shaped mem er of iron about veach contact fin er and an iron plate on each side of the conducting member align- B0 ed'with the U-shaped'members.

6. a circuit interrupter, a stationary contact memberfa movable switch member cooperating therewith for opening and closmeans including a member of magnetic mateto rial affixed to said movable switch member.

7: In a circuit interrupter, separable con-' tact members for opening and closing the circuit, said contact members having engaging contact faces, and a member of magnetic as material energized only when said separable contacts are in the closed position for exerting a force tending to press said contact faces toward'each other.

L, 8. In a circuit interrupter, separable contact members for opening and closing the circuit, said contact members having engaging contact faces,'and magnetic means ener-V gized by the current flowv through said separable members for biasing said engaging contact faces toward each other, said magnetic means including a substantially channel shaped member of magnetic material aflixed to and disposed about one of said engaging contact member s. I 1}",

9. In a circuit'interrupter, separable contact members for opening and closing the circuit, said contact members having engagin'g' contact faces, spring, means and magnetic means for'lbiasing said contact faces toward' eachother, said ma etic means-beenergiaedonlywhen said separable contacts-are injtli'e closed position, and includa, channel ibhaped member of magnetic materiaijgstenied to. one of said contact memhere 'aii'da member ofmagnetic material coting therewith, one of said separable ontact member'sfbeing'disposed between the legs; of said channel shaped member.

1 -10. In a circuit interrupter, a stationary contact member, a supporting means for. said contact. member, a movable switch member cooperating with said stationary qcontact member for opening and closing the circuit, saidstationary member and said switch mem- 12o ber having engaging contact faces, and magnetic means for biasing said contact faces toward each other, energized only when said circuit interrupter is in the closed position and including a member of magnetic material aflixed to said movable switch member and a member of magnetic material affixed to said contact supporting means. i

11. In a circuit interrupter, a stationary contact member, a movable switch member cooperating therewith for opening and closing the circuit, said stationary contact mem ber and said movable switch member having engaging contact surfaces, spring means for supplyin a predetermined normal contact pressure etween said engaging contact surfaces, and magnetic means energized by the current flow through said cooperating members for increasing the normal contact pressure between said engaging contact surfaces,

theincrease in contact pressure due to the b magnetic means being substantially proportional to the magnitude of the energizing current.

12. In a circuit interrupter, a stationary contact member, a supporting means for said contact member, a movable switch member cooperating with said stationarycontact member for opening and closing the circuit, said stationary contact I member and said movable switch member having engaging contact surfaces, spring means for supplying a predetermined normal contact pressure between said engaging contact surfaces, and magnetic means energized by the current flow through said cooperating members for bias ing said contact surfaces toward each other, said magnetic means including a member of magnetic material afiixed to said movable switch member and a member ofmagnetie material aflixed to said supporting means.

13. In a circuit interrupter, two separable contact members for opening and closing the circuit, said contact members having engaging contactvsurfaces, and magnetic means energized by the current flow through said separablemembers for biasing said engaging surfaces toward each other, said magnetic means comprising a channel shaped member of ma etic,,material aflixed to one of said separa 1e contact members and a cooperating means of magnetic material for attracting said channel shaped member, one of said separable contact members being disposed between the legs'of said channel shaped mem- 14. In a circuit interrupter, separable contact members for opening and closing the circuit, said contact members having engaging contact faces, spring means and marnctic means for biasing said contact faces toward each other, said magnetic means including a member of magnetic material fastened to one of said contact members and a member said magnetic means being said cooperating members for of magnetic material cooperating therewith, the magnetic circuit formed by said members of magnetic material having a gap of high reluctance therein when said separable contacts are in the closed position.

.15. In a circuit interrupter, two separable contact members for opening and closing the circuit, said contact members having engaging contact surfaces, and magnetic means for biasing said engaging surfaces. toward each other, said magnetic means comprising a channel shaped member of magnetic material aflixed to one of said separable contact members and a cooperating member of magnetic material for attracting said memberv of magnetic material, netic material being other at at least one point at all times during the operation of said interrupter, one of said separable contact members being. between the legs 16. In a circuit interrupter, astationary of said channel shaped memcontact member, a supporting means for said a movable switch member cooperating with said stationary contact member for opening and closing the circuit, said stationary member and said switch member having engagingcontact faces, ahd magnetic means for biasing said contact faces toward each other, said magnetic means including a member ofmagnetic material afcontact member,

fixed to said movable switch member and a member of magnetic material affixed to said contact supporting means, said members of magnetic material being separated from each other at all times at at least one point.

17. In a circuit interrupter, a stationary contact member, a supporting means for said contact member, a movable switch member cooperating with said stationary contact meml'ier for opening and said stationary contact member and said movable switch member having engaging contact surfaces, spring means for supplying a predetermined normal contact pressure between said engaging contact surfaces,'and magnetic means energized by the current flow through additional force biasing said contact surfaces toward each other, saidmagnetic means including a member of magnetic material affixed to said movable switch member and a member of magnetic material aflixed to said supporting means, said members of magnetic material being separated from each other at all times at at least one point.

ROSIVELL C. SICKLE.

disposed said members of mag- I separated from each ii I) closing the circuit,

supplying an 

